I have a first run Micro Trains N scale box car. I found out later in life that if I left it in the original blister pack and not run it it would have been worth a thousand times more then I bought it for. I learned of my misfortune reading an n-scale collector auction report.
Yes, and if I had kept my Star Wars action figures mint on the card when I was a kid in the late 70's, a few of the early ones would be worth a lot of money.
I was a normal kid though, I opened and played with them.
(This is also why 1952 Topps Mickey Mantle cards are valuable. As Lee p51 alludes to, the reason lots of stuff from those years was valuable later is because a lot didn't survive the years. In today's world, there are way too many people stowing stuff away for a "rainy day" fund that will never materialize.)
-Dave